1. Field of the Invention
The present invention relates to a liquid crystalline polyester resin composition which is suitable for being applied to optical pickup members such as a holder for optical pickup lenses, a base frame and the like, a molded article and a holder for optical pickup lenses.
2. Description of the Related Art
Hitherto, in response to a demand for a reduction in the weight of the optical pickup member of this kind, attempts to switch a constituent material of the pickup member from a metal material to a resin material were made. Particularly, since a liquid crystalline polyester resin composition containing glass fibers mixed is superior in mechanical properties, moldability, dimensional accuracy, heat resistance and a damping property among resin material, it is adopted as optical pickup members.
However, the demand for a damping property becomes severe with increases in capacity and speed of information which recent digital disk drive systems handle. As the countermeasure for this, it is required that a secondary resonance frequency of the optical pickup member is shifted to a high frequency side and a width of gain is enlarged, namely, that the rigidity of the optical pickup member is increased (resonance frequency is proportional to the half power of specific modulus; increases in a MD direction and a TD direction), it becomes clear that the conventional liquid crystalline polyester resin composition cannot response to this demand.
As the liquid crystalline polyester resin compositions which are suitable for these optical pickup members, a resin composition composed of liquid crystalline polyester and aluminum borate whiskers is disclosed (for example, JP-A-11-80517) and a resin composition composed of liquid crystalline polyester, glass fibers and spherical hollow bodies, which is aimed at reducing the weight, is disclosed (for example, JP-A-2004-143270).